Air induction system for an internal combustion engine

Abstract

An air induction system for an internal combustion engine has a dual choke inlet, a spindle passes diametrically across both chokes, a pair of throttle blades are secured to the spindle for rotation therewith, each throttle blade being located in a different one of the chokes, the throttle blades being angularly offset from each other.

I claim: 
     
       1. An air induction system for an internal combustion engine comprising a dual choke inlet with a pivotal throttle blade in each choke, the throttle blades being mounted for rotation together on a common spindle, the throttle blades being angularly offset from each other. 
     
     
       2. An air induction system as claimed in claim 1 wherein the common spindle is controlled by a motor responsive primarily to signals representative of the position of a driver operable accelerator control. 
     
     
       3. An air induction system as claimed in claim 1 wherein the system is used in conjunction with a multi-cylinder engine and wherein each choke leads to a respective separate plenum and each plenum feeds one set of cylinders. 
     
     
       4. An air induction system as claimed in claim 3 wherein a gate valve is arranged between the two plenums and is selectively openable to balance air flow to the two sets of cylinders at small throttle openings. 
     
     
       5. An air induction system as claimed in claim 1 wherein the offset angle between the two blades is between 3° and 10°. 
     
     
       6. An air induction system as claimed in claim 5 wherein the offset angle is between 4° and 6°. 
     
     
       7. An air induction system according to claim 1 wherein the spindle passes diametrically across both chokes and in the fully open state the blades have equal and opposite inclinations to air flow which are sufficiently small to avoid any significant increase in flow resistance over that of the spindle. 
     
     
       8. An air induction system as claimed in claim 1 for use with a fuel-injection multi-cylinder spark-ignition engine.